Behind the title of first novelist Khaled Hosseini's "The Kite Runner" lurks a metaphor so apt and evocative that even the author never fully exploits its power. For the benefit of readers who didn't grow up in Afghanistan -- as Hosseini and his alter ego Amir did -- a kite runner is a sort of spotter in the ancient sport of kite fighting. In a kite fight, competitors coat their kite strings in glue and ground glass, the better to cut their rivals' moorings. While the fighter's kite is swooping and feinting in an effort to rule the skies, his kite-running partner is racing to own the streets, chasing down all their opponents' unmoored, sinking trophies.

It's a fresh, arresting, immediately visual image, and Hosseini uses it well enough as a symbol for Amir's privileged Afghan childhood in the 1970s, when he and his faithful servant, Hassan, had the run of Kabul's streets. Near the novel's end, when the adult Amir returns in secret to Taliban-controlled, sniper-infested Kabul in search of Hassan's lost son, the contrast with his cosseted, kite-flying youth could scarcely be more pronounced, or more effective.

But Hosseini could have deepened the symbolism even further if he hadn't ignored what, in essence, a kite fight really is: a proxy war. Here's Afghanistan, jerked around like a kite for most of its 20th century history by the British, the Soviets,

the Taliban and us, played off against its neighbors by distant forces pulling all the strings, and Hosseini never once makes the connection. It's just too tempting a trick to leave on the table.

Of course, it's Hosseini's metaphor and he can do with it -- or not do with it -- as he pleases. Considering how traditionally and transparently he tells the rest of Amir's story, though, Hosseini wouldn't seem the type to go burying half-concealed ideas for readers to tease out. More likely, he instinctively hooked a great image but, alas, doesn't yet have the technique to bring it in for a landing. It's a small failing, symptomatic of this middlebrow but proficient, timely novel from an undeniably talented new San Francisco writer.

Hosseini's antihero Amir narrates the book from the Bernal Heights home he shares with his wife, Soraya. Like Hosseini, Amir's a writer, modestly celebrated for literary novels with such pretentious-sounding titles as "A Season of Ashes."

But Amir's childhood in Kabul still haunts him, specifically his mysterious inability to earn the love of his philanthropically generous but emotionally withholding father, and his guilt about failing to protect his angelic half- caste old kite runner, Hassan, from a savage assault. When Amir receives a deathbed summons from his father's business partner in Pakistan, he sees a chance to redeem himself from the secrets that have left him psychically stranded between Afghanistan and the United States.

Unfortunately, we know all this because Amir tells us, and not just once. Listen to him here, on the verge of his rescue mission over the Khyber Pass: "I was afraid the appeal of my life in America would draw me back, that I would wade back into that great, big river and let myself forget, let the things I had learned these last few days sink to the bottom. I was afraid that I'd let the waters carry me away from what I had to do. From Hassan. From the past that had come calling. And from this one last chance at redemption."

One might excuse all this melodramatic breathlessness as the reflexive self- examination of a character who, after all, writes novels with titles like "A Season of Ashes." But Amir's not the only one given to overly explicit musings.

His father's old partner goes in for it too, in a letter to Amir: "Sometimes, I think everything he [your father] did, feeding the poor on the streets, building the orphanage, giving money to friends in need, it was all his way of redeeming himself. And that, I believe, is what true redemption is, Amir jan, when guilt leads to good." A fine thing, redemption, but better implied than stated -- let alone restated.

Hosseini shows a much more natural talent when he stops telegraphing his themes and lets images do the work for him. All the material about the Afghan expatriate community in Fremont is fascinating, especially the scenes of Amir and his once-prosperous father making the rounds of weekend garage sales. They take all their underpriced finds to swap meets and resell them, thus augmenting the father's paltry income from his gas station job, so that Amir can study writing at Ohlone Community College. Maybe we've seen similar immigrant stories before -- the defrocked Iranian colonel of Andre Dubus' "House of Sand and Fog" comes to mind -- but Hosseini imparts a delicacy here that transcends any mere topical curiosity about Afghanistan.

Would "The Kite Runner" have been published if the United States hadn't briefly entertained an interest in all things Afghan? Maybe not, but sometimes decent books come out for the wrong reasons. Hosseini has taken the sorrowful history of his tragically manipulated birthplace and turned it into informative, sentimental but nevertheless touching popular fiction. For every misstep, as when he says that his father faced the loss of his former station "on his own terms" (whatever that tired, blurry phrase might mean), there's a grace note, as when a traumatized catamite is described as walking "like he was afraid to leave behind footprints."

In the annual literary kite fight for summer readers -- with Afghanistan now well down any list of the nation's current preoccupations -- Hosseini may wind up with his strings sliced out from under him. Just don't be surprised if his modest but sturdy storytelling skills, once cut loose from the crosswinds of a cynical seasonal marketplace, someday find their way to an updraft.